Library devices are known as devices used to store numerous data. A library device includes a magazine serving as a storage rack that can store a number of record media, a drive that executes read/write processes for record media, and an accessor that carries record media from a magazine to a drive. The magazine can be detachably attached to the library device, wherein the magazine has a plurality of slots for loading a plurality of record media.
Various documents are known about library devices. For example, Patent Literature 1 discloses a library device equipped with an error insertion-preventing mechanism and an ejection receiving mechanism while Patent Literature 2 discloses a library device equipped with a magazine holding structure that can change a drawing amount of a magazine in a stepwise manner.
Due to an error occurring in record media of a library device, it is necessary to remove a magazine holding erroneous record media. That is, an operator needs to open a magazine and thereby remove erroneous record media. When an operator open a magazine in a library device, it is necessary to carry out an inventory operation to confirm the presence/absence and allocation of record media with respect to all the slots in a magazine.
Patent Literature 1 and Patent Literature 2 discloses technologies concerning magazines that allow part of slots to be pulled out. That is, it is possible to reduce an execution time for an inventory operation by executing an inventory operation for part of slots being drawn out from a magazine.